Abstract TMP25: Rates of Complications and Aneurysm Occlusion in Patients Undergoing Treatment of Cerebral Aneurysms Utilizing Flow Diversion with the Pipeline Embolization Device and Algorithm Adjusted Antiplatelet Therapy

Introduction: The need for therapeutic dual antiplatelet therapy in patients with cerebral aneurysms treated with flow-diverting stents increases the risk of thromboembolic and hemorrhagic complications. To balance these risks, we assessed patients for their responsiveness to dual antiplatelet therapy using a modified platelet aggregation study (PIPA). We hypothesized that double doses of clopidogrel or aspirin in patients with antiplatelet non-responsiveness would reduce the incidence of thromboembolic complications without increasing the incidence of hemorrhage or decreasing the rate of aneurysm occlusion. Methods: 79 patients with 98 cerebral aneurysms were treated with the pipeline embolization device. All patients with a suboptimal PIPA received double doses of clopidogrel or aspirin prior to treatment. Aneurysm occlusion was categorized using the Roy-Raymond Occlusion Classification (RROC). Chi-square or Fisher’s exact tests were used for univariate analyses, and logistic regression was used to identify potential predictors of complications and aneurysm occlusion. Results: Seven patients had a major complication and 7 had a minor complication (8.9%). There were 3 cerebral ischemic strokes (3.8%) and 5 cerebral hemorrhages (6.3%). Thirty-eight patients had angiographic follow-up at 6 months. Of these, 18 patients were resistant to clopidogrel or aspirin, and 19 received double dose therapy prior to treatment. Double dose clopidogrel or aspirin was not associated with major, minor, cerebral ischemic or hemorrhagic complications. Twenty-one patients (55.3%) had complete occlusion of their aneurysms (RROC type 1), and 17 patients were categorized as RROC type 2 or 3 at 6 months. Treatment with double dose clopidogrel or aspirin was not associated with reduced occlusion (RROC type 2 or 3) in a univariate and multivariate analysis. Conclusions: In patients treated with flow-diverting stents, the risk of ischemia must be balanced with the risk of hemorrhage. We found that the use of double dose clopidogrel and aspirin in the setting of antiplatelet non-responsiveness is safe. It is not associated with increased hemorrhagic complications. Patients treated with double dose therapy did not exhibit a reduced aneurysm occlusion rate.